I own a pair of 7x50 Celestron Ultimas and while they show fairly nice pinpoint stars in the center, at about a 1/3 of the field edge is distorted. I recently looked through a pair of Oberwerks 9x60's and they had about the same distortion as the C-Ultimas. While looking at a star field through these binoculars in the center sweet spot, the edge of field distortion is hard to discern because that area is using the eye's per peripheral vision. But if I center my eye towards the edge I then see the distortion. Do higher quality binoculars have better correction (flat field) or is this just the nature of the optics? Zeiss, APM, etc?
Anyone know of any discussions/articles on edge of field comparisons between brands.
Thanks for any info